Display call member speaking status on bottom bar (#2742)

* add mutation observer hok

* add hook to read speaking member by observing iframe content

* display speaking member name in call status bar and improve layout

* fix shrining

src/app/features/call-status/styles.css.ts

@@ -15,3 +15,7 @@ export const CallStatus = style([
 export const ControlDivider = style({
   height: toRem(16),
 });
+
+export const SpeakerAvatarOutline = style({
+  boxShadow: `0 0 0 ${config.borderWidth.B600} ${color.Success.Main}`,
+});